Apparatus for coating surfaces



March 1, 1938. M NORTH 2,109,647

APPARATUS FOR COATING SURFACES Filed Nov. 6, 1935 2 Sheets-Sheet lINVENTOR.)

Mortimer dJVorZh) a y a ATTORNEY.

March 1, 1938. M. 5. NORTH 2,109,647

APPARATUS FOR COATING SURFACES Fil d Nov. 6, 1935 2 Sheets-Sheet 2ATTORNEY.

Patented Mar. 1, 1938 UNITED STATES PATENT OFFICE 17 Claims.

This invention relates to the coating of paper, or other sheet material,with paint, enamel, rubber or other viscous liquids, for variouspurposes.

Generally stated, the object of the invention is to provide an improvedapparatus for the coating of paper, or other sheet material, by forcingthe viscous liquid through a wire screen, or screen of any suitablematerial, onto the surface of the paper or other sheet material, tothereby insure a uniform thickness for the coating thus applied to thesheet material, as well as a perfectly smooth and even surface therefor,in the production of coated paper, or other sheet material.

It is also an object to provide certain details and features ofconstruction tending to increase the general efficiency and desirabilityof an apparatus of this particular character.

To the foregoing and other useful ends, the invention consists inmatters hereinafter set forth and claimed and shown in the accompanyingdrawings, in which- Fig. 1 is a diagrammatic view of an apparatusembodying the principles of the invention, showing the same in normalcondition, before the paper is inserted for treatment.

Fig. 2 is a similar view showing the apparatus in operation, with thepaper being given the required coating.

Fig. 3 is an enlarged diagrammatic view showing certain details moreclearly, with the elements in the same condition in which they are shownin Fig. 1 of the drawings.

Fig. 4 is a similar view, showing the elements in the same condition inwhich they are shown in Fig. 2 of the drawings.

Fig. 5 is an enlarged detail section on line 5-5 in Fig. 4 of thedrawings, showing a certain size wire for the screen.

Fig. 6 is a similar view, showing a sma'ilersize wire for the screen.-

Fig. '7 is a detail sectional view, showing the thickness of coatingresulting from the use of the screen shown in Fig. 5 of the drawings.

Fig. 8 is a similar view showing the thickness of coating resulting fromthe use of the screen shown in Fig. 60f the drawings.

As thus illustrated, referring to Figs. 1 and 2 of the drawings, theinvention comprises a relatively large main roll I, having a portion ofits periphery provided with a felt cushion 2, with a clip 3 at theforward edge of said cushion to grip the sheet of paper 4, which latteris supported on the inclined table 5, as shown. The lower and smallerroll 6 is operated in any suitable or desired manner, so that both rollsrotate or travel in the direction indicated by the arrows, and the roll6 is supported by a receptacle 1 containing the paint or enamel orrubber or other viscous material 8, to be applied to the paper or othersheet material. The receptacle 1 is moved up and down by any suitablemeans, such as the cam 9, so that the two rolls are relatively movabletoward and away from each other, the receptacle I being pivoted at Illfor this purpose. A wire screen H is disposed between the two rolls, asshown, with its end portions wound on the rolls l2 and is, these screenrolls rotating in the direction indicated by the arrows, to feed thescreen periodically between the two rolls I and 6, previously mentioned.In practice, the feeding stroke is about an inch, so that after eachcoating operation, a section of fresh screen is fed between the tworolls I and 6, as will hereinafter more fully appear, the screen beingsupported intermediately by the idler roll H, as shown. Any suitablemeans can be employed for intermittently rotating the rolls l2 and IS inproperly timed relation to the other elements of the apparatus.

Assuming that the apparatus has been started, the rolls l and 6 arebrought together, as shown in Fig. 2 of the drawings, with the paper 4between the felt 2 and the screen II, with enough pressure to insure thecoating of the under side of the paper. The film of viscous liquid,carried upwardly by the roll 6, is pressed through the meshes of thescreen against the under side of the paper, while the latter is beingcarried along by the rotation of the roll I, and during this time thescreen II is standing still, but the roll 6 is rotating to feed theviscous liquid to the lower surface of the paper, through the meshes ofthe screen, as stated, and as illustrated in Fig. 4 of the drawings. Assoon as the entire surface of the paper has been coated, the roll 6moves downwardly, as a result of the action of the cam 9, and beforeanother sheet of paper has been brought into position to be coated, therolls l2 and I3 are actuated to feed about an inch, more or less, offresh screen into position for the next operation, whereby a perfectlyclean and fresh section of the screen is fed into position, for eachsheet of paper. The clean screen, therefore, is unwound from the rollI3, and the sticky or used portions of the screen are wound on the rolll2. After the entire length of the screen has been used, it is taken offand washed and thoroughly cleaned, before it is put back in the machineor apparatus thus provided for coating the paper.

The screen may be made of wire of different sizes, but preferably finewire is employed, and it is found that screen of 120 mesh doessatisfactory work. It is also found that the size or auge of the wireapproximately determines the thickness of the coating left on the paper.In Fig. 5, the wire is of larger gauge, with the result that the coatingi5 is thicker, whereas in Fig. 6 the screen is of fine gauge wire, withthe result that the coating I5 is thinner. As shown in Fig. 4, the filmof viscous liquid l6 travels upwardly on the surface of the roll 8,during the operation of actually coating the paper, is squeezed throughthe screen ll against the paper 4, and emerges above the screen as thesaid coating IS on the lower side of the paper. The latter can be takenout in any suitable or desired manner, as by feeding it into a belt ll,as shown in Fig. 1 of the drawings.

It is important to observe that the wire screen, or a screen made ofsilk or any other porous matcrial, of the proper mesh, is stationaryduring the time that the viscous liquid is being squeezed through it onthe under side of the paper. This is highly desirable, if not absolutelynecessary, for the reason that should the screen be permitted to travelin synchronism with the paper, a stenciling effect on the latter wouldbe the result. However, by keeping the screen stationary, the minutequantities of liquid, that are forced through the screen onto the paper,are merged uniformly into a continuous coating on the under side of thepaper, of uniform thickness, and the surface of the coating becomesperfectly smooth and even and free from streaks or undulations, when thecoating is finally dried.

Thus, the invention provides an apparatus for applying liquids ofdifferent kinds, or substances of more or less liquidity or plasticity,to the surface of paper or other sheet material, in a more satisfactorymanner than was possible with certain kinds of apparatus heretoforeemployed for this purpose, inasmuch as the forcing of the liquid ormaterial through the proper screen, which is stationary during theoperation, insures a more satisfactory product, with low cost ofproduction.

It will be seen, therefore, that the invention comprises a fountainsupply means, in this case in the form of a receptacle and a roller, forforcing the stationary screen against the revolving sheet material, sothat the latter is subjected to a rubbing effect on the screen, in amanner to pull the more or less liquid material through the intersticesof the screen, so that the material will be spread evenly and uniformlyover the surface of the paper or other sheet material. Preferably, asshown, both the receptacle I and the roll 6 of the said fountain supplymeans are movable up and down, to force the screen against the paper,but it is obvious that the necessary or desired pressure can be providedby any suitable or desired means, and the invention is not limited tothe exact construction shown and described.

With the viscous liquid material thus applied under pressure, to thesurface ofthe paper, it is found that a much thicker or heavier viscousliquid material can be used, than is ordinarily possible, and that tinyor microscopic hairs or portions of the fiber that are ordinarily foundon the surface of the paper, are completely imbedded below the surfaceof the coating and are not allowed to remain projecting from saidsurface, whereby the latter is smooth and glossy and entirely free fromany projecting hairy or fibrous portions of the paper.

So far as the screen being stationary is concerned, that is essential tothe invention, it will be seen, only during the frictional rotatingaction of the screen on the surface of the paper or other sheetmaterial. Therefore, by "stationary screen is meant a screen which isstationary while the coating material is being forced through the screenonto the surface of the paper or other sheet material. At other timesthe screen might or might not have movement or motion, so far as thebroader aspects of the invention are concerned, but more specificallyconsidered, as shown and described, the screen does have motion when notin use, in order to substitute a fresh section of the screen for a usedsection thereof.

What I claim as my invention is:

1. In a machine for coating sheet material, means to support the sheetmaterial for motion, a screen suitably supported to remain stationaryduring the operation of the machine, a fountain supply means forapplying the more or less liquid material to the surface of the sheetmaterial, while the latter is moving, and means for exerting pressurethrough said fountain supply means to force the screen against thesurface of said sheet, and to force the liquid through the screen ontothe sheet.

2. A structure as specified in claim 1, said screen being flexible, tofacilitate the said forcing action, and being supported on rolls topermit a fresh section of the screen to be brought into position foruse, to take the place of the preceding used section.

3. A structure as specified in claim 1, said fountain supply meanscomprising a roll for directly engaging the screen, the latter beingflexible to plerntit the said forcing thereof against the moving s cc 4.A structure as specified in claim 1, the means for supporting the sheetmaterial comprising a roll with means for holding the sheet on thecircumference thereof.

5. A structure as specified in claim 1, said support for the sheetmaterial being adapted to force the sheet against said screen, wherebythe latter is squeezed tight between the sheet and the fountain supplymeans, and the moving sheet is squeezed tight between its support andthe screen, while the latter remains stationary.

6. Apparatus for coating paper or other sheet material, comprising ascreen, supporting means for holding the paper and frictionally rubbingthe surface of the sheet over one surface of said screen, means forholding the screen in stationary position for use, so that the screenand paper have relative frictional sliding movement, while the coatingmaterial is passing through the stationary screen, and instrumentalitiesfor applying the material for the coating, in more or less liquid orplastic condition, through the screen from the other side of the latterto the surface of the sheet, while the latter is traveling edgewise onthe screen.

7. A structure as specified in claim 6, said supporting means comprisinga cylindrical roll for curving the paper on the surface thereof, so thatsuccessive sections of the paper are brought successively into contactwith the screen.

8. A structure as' specified in claim 6, said in strumentalitiescomprising a roll arranged to rotate in the said material for thecoating, to feed the latter to the meshes of the screen.

9. A structure as specified in claim 6, said supporting means beingabove the screen, and said instrumentalities being below the screen, sothat said material for the coating is forced upward through the screenagainst the lower side of the paper, said supporting means comprising aroll for curving the paper on the surface thereof, so that successivesections of the paper are brought successively into contact with thescreen, and said bearing means comprising a roll for rubbing saidcoating material against the lower side of the screen.

10. A structure as specified in claim 6, comprising means forintermittently feeding the screen forward, thereby to bring a freshsection thereof into position for use, after each coating operation.

11. In apparatus for giving paper or other sheet material a coating ofviscous liquid material, the combination of means for movably supportingthe paper or other sheet material, in a manner to resist pressureexerted against the paper, a stationary screen uniformly engaging themoving surface of the paper or other material, and means for applyingthe liquid material through said screen under pressure and friction tothe surface of the sheet material, while the latter is moving.

12. A structure as specified in claim 11, the means for applying theliquid material comprising a fountain supply having a rotating feedroller for feeding and pressing the liquid material through said screenupon the surface of the paper or other sheet material.

13. A structure as specified in claim 11, the support for the papercomprising a rotary member having a cylindrical surface to receive thepaper or other sheet material, adapted to cause a rubbing action againstthe coating while the latter is being applied, together with means forperiodically moving fresh sections of the screen into position forstationary use.

14. A structure as specified in claim 11, the support for the papercomprising a rotary member having a cylindrical surface to receive thepaper or other sheet material, adapted to cause a rubbing action of thescreen against the paper and coating while the latter is being appliedthrough the stationary screen.

15. Apparatus for coating paper with a viscous liquid, comprising meansfor backing and supporting the paper in position to resist pressure onthe surface thereof, and perforate means having frictional engagementwith the surface of the paper to exert a rubbing action thereon,progressively along the surface thereof, for supplying and rubbingliquid on the sheet under pressure, and moving means for rubbing theliquid through said perforate means onto the paper.

16. A structure as specified in claim 15, comprising means for movingthe sheet support during the coating operation, and means for holdingthe said rubbing means relatively stationary, so that the rubbing actionis caused by the movement of the paper.

17. In apparatus for giving paper or other sheet material a coating ofviscous liquid material, the combination of means for supporting thepaper or other sheet material, in a manner to resist pressure exertedagainst the paper, and means including a screen uniformly engaging thesurface of the paper or other materiaL'for applying the liquid materialunder pressure to the surface of the paper or other sheet material, themeans for applying the liquid material comprising a fountain supplyhaving a rotating feed roller for feeding and pressing the liquidmaterial through said screen uponthe surface of the paper or other sheetmaterial.

MOR'I'IMER 8. NORTH.

